Tuna butchering method and system

ABSTRACT

An automated butchering method and system for separating the edible loin portions of transverse tuna slices provided by subdivision of a frozen whole tuna. Each transverse slice of the principal loin bearing section of a frozen tuna is scanned to produce electrical signals representative of the boundary between the edible loin portions and the contiguous waste meat portions. Control signals can be derived from these electrical signals for government of cutting apparatus for precise separation of the edible loin portions along the detected boundary.

United States Patent 1 Lapeyre TUNA BUTCHERING METHOD AND SYSTEM [75]Inventor: James'M. Lapeyre, New Orleans,

[73] Assignee: The Laitrom Corporation, New

Orleans, La.

[22] Filed: Dec. 29, I972 211 Appll No.1 319,663

[52] US. Cl 17/52, l7/54, 17/61 [51] Int. Cl. A22c 25/18 [58] Field ofSearch 17/52, 54, 61, 55, 56

[56] References Cited -UNlTED STATES PATENTS Lapeyre l7/52 Apr. 2, 1974Primary Examiner-Robert Pcshock Assistant Examiner- -D. L.-WeinholdAttorney, Agent, or FirmWeingarten, Maxham & Schugin ABSTRACT 16 Claims,8 Drawing Figures SCANNER CONTROLLER CUTTING CUTTING POSITION APPARATUSAPPARATUS PATENTEDAPR 2191; v SW10 3800.363

A15 E I197: 1: 131 I is Mi K5? K62 K64 K66 CUTTING SCANNER CONTROLLERPOSITION gg JES APPARATUS F-Tig. 5.

m THRESHOLD LIGHT ClRCUlT 5E OUTPUT SIGNAL PATENTED APR 2 I874 SHEET 2UF 2 L WA N um 08 OUTPUT SIGNAL 1 TUNA BUTCHERING METHOD AND SYSTEMFIELD OF THE INVENTION This invention relates to the commercialbutchering of tuna fish and more particularly to an automated method andsystem for separating the edible loin portions from waste portions.

BACKGROUND OF THE INVENTION Commercial tuna processing remains anessentially manual process in which a multiplicity of individual handoperations are required to separate the edible loin portions of tunafish from the waste meat and skeletal structure. Such mechanizationwhich has occurred in the industry has been with respect to improvedrefrigeration, machinery for conveying the fish or its constituentsduring the processing operation, and machinery for packing the meatintocans.

In the usual processing of tuna for canning purposes, the fishisprecooked and is then cooled and routed to work tables for manualmanipulation and cleaning. The

head and tail'are removed and the skin and fins are scraped off, afterwhich the tuna is split longitudinally and the backbone removed. Eachhalf of the split tuna is again longitudinally split to form a pair ofdiscrete dorsal loins (the right and left epaxial muscles), and a pairof discrete ventral loins (the right and left hypaxial muscles). Theblood meat and associated dark meat portions are scraped away from theedible loin portions, and the remaining loins, edible flakes and wasteproducts are routed to separate processing stations for furtheroperations to provide respective products. Each of the steps of theprocessing sequence outlined above is essentially manual in characterand the rate at which the tuna is processed and the quality of theresulting work is quite variable depending upon the skill of theindividual worker.

Significantly improved tuna butchering techniques are the subject of US.Pat. Nos. 3,593,370 and 3,594,191 of]. M. Lapeyre, and .which areassigned to the assignee of the present invention. In the novel methodsof the foregoing patents, the tuna is subdivided in its frozen stateinto a pluralityof cross sectional or transverse slices and the edibleloin portions are then separated from the waste meat and bone portionsof each slice. It issignificant that the butchering of the tuna isaccomplished before any cooking operation. The edible loin portions arecooked separately from the waste products, and as a result, staining ofthe meat is avoided thereby improving the yield of canned meat. Suchstaining of the edible meat can and usually does occur in theconventional processing of tuna, since the entire fish is precookedprior to butchering.

The separation of the edible loin portions in each transverse tuna slicecan be accomplished manually or by use of suitably configured dies. Thedies are typically of quadrant shape and are sized in accordance withthe physical characteristics of the tuna slices, which are usuallypresorted to provide more uniformly sized slices for cutting at aparticular work station. The cutting diesare of fixed size andconfiguration, while necessarily the edible loins of the tuna slices areof variable aspect. As a result, the edible loin portions areimperfectly separated in that some of the edible meat may not be cut bythe die, or the separated loin may include some amount of waste meat. Itis an object of this invention to provide a butchering technique and themeans for separation of the edible loin portions of tuna slices fromassociated waste portions along the actual boundary of the edible loinsof slices being butchered, rather than along a boundary presumed forparticular slices.

For purposes of this application, the term tuna will, because ofconventional usage within the industry, be considered to include thefollowing species of fish: albacore (Germo alalunga), bluefin (thunnusthynnus), skipjack (Katsuwonus pelamis), yellowfin (Neo-thunnusmacropterus), little tuna (Ethynnus alletteratus), Atlantic bonito(Sarda sarda), Pacific bonito (Sarda chiliensis), and yellowtail(Seriola dorsalis).

The initial five species identified immediately above are recognized asspecies of tuna, the bonito and yellowtail being tuna-like fish as theyare commercially canned tuna-style, although such canned fish cannot bedomestically labeled as tuna.

SUMMARY OF THE INVENTION In accordance with the invention, an automatedbutchering method and system is provided for determining the actualboundary between the edible loin portions of a frozen transverse tunaslice and the associated waste meat portions, and for providingelectrical signals representative of the detected boundary and inresponse to which cutting apparatus can be controlled for preciseseparation of the edible loin portions. By virtue of the invention,substantially all of the edible loin portions are separated forsubsequent cooking and canning without contamination by a layer of bloodmeat or skin which can remain, if tuna is butchered by conventionaltechniques.

In practicing the invention, a frozen whole-tuna is subdivided bycutting the loin-bearing portion thereof into a plurality of discretetransverse slices of predetermined thicknesses. The boundary of theedible loin portions of each transverse frozen tuna slice is determinedby scanning a surface of the slice to provide a signal indication of thereflectivity thereof, which differs for the loin portions, and the wastemeat portions which include'the blood meat, skin and viscera. Manydifferent scanning instrumentalities can be employed according to theinvention to provide the signals indicative of the edible loinboundaries. Scanning of the transverse tuna slice can be accomplished,for example, by mechanical means whereby a slice is moved relative to asensor to provide the delineating signals. Usually, the sensor would bestationary while the tuna slice is caused to move past thesensingstation. Another form of scanner employs electronic or opticalscanning wherein a beam of light or other suitable radiant energy iscaused to traverse the tuna slice along a predetermined path to providethe intended output signals. The resulting signals can be subsequentlyemployed to control the movement of cutting apparatus for separation ofthe edible loins from the remainder of the slice. The invention alsocomprehends the scanning of both surfaces of a frozen tuna slice toprovide signal indications of the loin boundaries of the respectivesurfaces for use in adjusting the cutting angle of the cutting apparatusto follow the loin boundaries which can be tapered through the slice byreason of anatomical configuration.

The bone structure of a tuna slice cannot usually be differentiated fromthe associated edible loins by optical scanning techniques; however, theposition of the bone structure is readily determined by virtue of thebilateral symmetry of the transverse slice and the central location ofthe structure. In alternative embodiment, the transverse tuna slice canbe cut along planes parallel to the neural spines of the skeletalstructure to provide right and left halves of a transverse slice. Eachhalf of the slice can then have the edible loins separated therefromalong the delineated boundary with the blood meat portions.

DESCRIPTION OF THE DRAWINGS The invention will be more fully understoodfrom the following detailed description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a perspective view of a frozen tuna which has been dividedinto a number of transverse slices;

FIG. 2 is a perspective view of a typical transverse tuna slice forbutchering according to the invention;

F IG. 3 is a block diagram representation of a system for butcheringtuna according to the invention;

FIG. 4 is a diagrammatic representation of a scanning system usefulaccording to the invention;

FIG. 5 is a diagrammatic representation of an alternative scanningsystem useful according to the invention;

FIG. 6 is a diagrammatic representation of a further alternativescanning system useful according to the invention;

FIG. 7 is a perspective view of a transverse tuna slice illustrating abutchering step of the invention; and

FIG. 8 is a perspective view of the edible loin portions separated froma transverse slice according to the invention.

DETAILED DESCRIPTION OF THE INVENTION For butchering according to theinvention, a tuna which is in frozen or substantially frozen conditionis subdivided into a plurality of discrete lateral or transverse slicesas described in the above-noted US. Pat. Nos. 3,593,370 and 3,594,191.As shown in Hg. 1, the loin-bearing portion of a tuna 10 is divided intoa plurality of transverse slices, such as slices 12 through 28 shown, bycutting the loin-bearing portion along axes generally transverse to thelongitudinal spine or backbone 30. The head portion 32 and tail portion34 are removed for separate processing, and the transverse or lateralslices of the loin-bearing portion are of a form which markedlyfacilitates the butchering and subsequent processing of tuna byautomated techniques according to the invention. The slices arepreferably of uniform thickness and of a thickness suitable to the typeand size of pack for which the tuna is intended.

It will be appreciated that the tuna slices are bilaterally symmetricalabout a dorsal to ventral plane, which permits individual slicesobtained from different tuna to be sorted into predetermined groupingsaccording to the general internal anatomical characteristics, to therebyfacilitate subsequent processing. The diametric size and anatomicalcharacteristics of individual slices for a particular tuna will vary inaccordance with the location from which the slice is derived and thesize and specie of the particular tuna. As seen in FIG. 1, both thevisceral cavity 36 and the blood meat portions 38 vary in size and crosssectional configuration according to the location within the tuna of theparticular slice.

A typical tuna slice 40 to be butchered according to the invention isdepicted in FIG. 2 and includes a centrally located and axially disposedportion of the spine or backbone 30 having neural spines 42a extendingupwardly and downwardly, and epicentral ribs 42b extending laterallytherefrom. The right and left epaxial muscle portions 44 and 46 and theright and left hypaxial muscle portions 48 and 50 constitute,respectively, the edible dorsal loins and edible ventral loins. Thedorsal and ventral loin portions are at least partially separated bylaterally extending blood meat portions 38. The ventral loin portionsalso merge into a relatively thin belly meat portion 52 surrounding thevisceral cavity 54. By operation of the invention, these edible loinportions are accurately delineated from the associated waste meatportions and cut therefrom to provide efficiently removed edible meatwhich is then cooked and packed for canning.

The surface reflectivity of the transverse tuna slice is sufficientlydifferent for the edible loin portions and for the waste meat portionsthereof to permit delineation of the edible loins by optical scanningtechniques. Specific reflectivities will, of course, depend upon thesurface characteristics of a particular slice, but, in general, thereflectivity of loin portions 44, 46, 48 and 50 is approximately twicethat of blood meat portions 38, viscera 54 and surrounding skin 56. Theboundary separating the lighter edible meat from the surrounding darkerwaste meat is quite sharp, which allows extremely precise delineation ofthe edible loin portions.

A system for delineating the edible. loin portions of a tuna slice isgenerally shown in FIG. 3 and includes a scanner 58 operative to scanthe surface of a tuna slice 60 and to provide output signals indicativeof the reflectance characteristics of the surface being scanned and fromwhich is derived a signal representation of the boundary between theedible loins and the waste meat portions. The output signals of scanner58 are applied to a controller 62 which provides control signals tocutting position apparatus 64 operative to control the position ofcutting apparatus 66 relative to slice 60 being butchered. The scanner58 can take a variety of forms which per se are known in the art ofoptical character recognition and mark sensing. For purposes ofillustration, several categories of scanners will be briefly describedas examples of instrumentalities which can be employed according to theinvention to provide novel tuna butchering.

One form of scanner is depicted in FIG. 4 and includes an elongatedphotosensor array 68 arranged to receive light reflected from thesurface of a tuna slice 70 and provided by a light source 72. The lightsource provides an elongated narrow beam of light which extends acrossslice 70, reflected light being directed to sensor 68 by lens system 74.The slice 70 is caused to move along an axis generally orthogonal to theaxis of the impinging light beam, as shown by arrow 76, such that thesurface of slice 70 is scanned to provide output signals representativeof the reflectivity of the scanned surface. The electrical signalsprovided by sensor array 68 will be of varying magnitude in accordancewith the varying reflectivity of the slice surface being scanned. Theseelectrical signals are usually processed by a threshold circuit 78 whichprovides a threshold level above which signals are presumed to berepresentative of the lighter edible loin portions and below which thesignals are presumed to be representative of the relatively darker wastemeat portions. The threshold circuit therefore provides an array ofelectrical signals of first or second digital value representing theedible loin and waste meat portions of the scanned tuna slice surface.These signals are then subsequently processed to provide control signalsfor associated cutting apparatus. The transformation of the scanneroutput signals into control signals for the cutting apparatus can beaccomplished by means and techniques well known in the electronics artand can include, for example, a special purpose electronic controller ora suitably programmed computer to provide cutting control signals.

A second embodiment of a scanner useful in the invention is shown inFIG. 5 wherein a video detector 80,

. such as a television camera or flying spot scanner, is

disposed to view the surface of a tuna slice 82 and to provideelectrical output signals representative of the surface characteristicsthereof for delineation of the edible loin portions, as discussed. Alight source 84 is provided to illuminate the surface being scanned, andvideodetector 80 is operative toelectronically scan the surface of thetuna slice in a predetermined path to produce corresponding electricalsignals representative of the reflectivity of the scanned path. Theelectrical output signals from detector 80 can then be processed asdescribed to control operation of a cutting tool. In this embodiment,relative motion between the tuna slice and the detector is not requiredas scanning is accomplished by electronic movement of an electron beamwithin the detector. Scanning of a stationary tuna slice can also beaccomplished by optical means wherein a light beam is caused to traversethe surface of the slice in a predetermined path by means of movablescanning mirrors.

Scanning of the tuna slice can also be accomplished manually such asshown in FIG. 6. A graphic data input tablet 86 includes a transparentplate 88 which is positioned over a slice 90 to be scanned. Such datainput gular coordinate driving signals to position the cutting head andcause it to follow a path along the predetermined boundary of the edibleloin portions of the tuna slice. Other cutting apparatus can also beemployed as desired, such as a knife blade or ultrasonic cutter.

The viscera exhibits a lower reflectivity than the edible loin portionsand can also be delineated during the scanning operation. However, it isnot usually necessary to remove the viscera by cutting, as in the frozenstate the viscera can be simply removed by forcing it out through thelarger end of the visceral cavity. A suitably configured plunger,conforming to the general cross sectional area of the smaller end of thecavity, can typically be employed for this purpose. Such a plunger canbe positioned automatically in response to the electr'ical signalsprovided by the scanner.

tablets are per se known and are operative to provide I output signalsrepresentative of the position of a stylus 92 which is manually movableabout the surface of plate 88. An operator can manually move stylus 92along the boundary of the edible loin portions of slice 90 to provideelectrical output signals representative of this boundary and whichcanbe employed to operate cuttingapparatus as described above. For amore fully automated system, however, the automatic scanning techniquessuch as those described above are preferable since no operator. need beinterposed to accomplish delineation of the edible loins.

The cutting apparatus for cutting the edible loin portions along thepredetermined boundaries is preferably a high pressure water jet cutter.Such water jet cutters typically operate at a pressure of about 30,000to 75,000 psi and employ a jet of about 0.005 to 0.015 inch diameter tocut through the frozen tuna slice. A pressure of 40,000 psi and a 0.007inch nozzle have been found satisfactory as an example. Such cutters aretypically'operative at a rate of 300 inches per minute cutting withoutcontact by a cutting tool. The water jet cutter is typically mounted ina movable head which is capable of movement along mutually orthogonalaxes such that the cutting head can be controlled by rectan- Accordingto a further aspect of the invention, the surface of the tuna slice canbe thawed prior to the scanning thereof in order to remove the surfacelayer of frost which may have formed and which may reduce the contrastof the relative portions of the slice which are to be scanned. Byremoval of the frost layer, the reflectivityof the edible loin and wastemeat portions is usually increased with the result that scanning signallevels of increased magnitude can be produced. Such increased signallevels are often advantageous in enhancing the performance of theassociated photosensor, and can permit the use of certain types ofsensors which require relatively high signal levels for properperformance.

It is sometimes desirable to peel away the skin surrounding the frozentuna slice prior to the butchering thereof and such peeling can beaccomplished by thawing the circumferential surface of the slice eitheras a separate step or during the thawing of the scanned surface torender the skin pliable to a degree sufficient to permit its removalfrom the otherwise frozen tuna slice.

The skeletal structure of the tuna slice is not readily discernible byoptical scanning techniques; however, the position of this structure canbe readily determined by reason of the bilateral symmetry of theanatomical configuration of the transverse slice and the centraldisposition of the skeletal structure. The neural spines which generallyseparate the right and left loin portions are disposed along an axiswhich substantially bisects the slice. The neural spine position canthus be ascertained by determining the center line of the blood meatportions which are delineated by scanning of the slice,

. as described. Removal of the edible loin portions from the associatedbone structure can be accomplished by cutting the transverse slice alongplanes parallel to the neural spines such as shown by dashed lines 94 inFIG. 7. Sucha cut can be accomplished by a water jet cutter or knifeblade, for example, to remove the neural spines 96 and a slight portionof contiguous meat 98. This cut can be taken either before or afterscanning of the slice. If the cut is provided after scanning of theentire slice, the boundaries of the edible loin portions and thecontiguous blood meat portions complete the separation of the edibleloins, such as illustrated in FIG. 8.

. In the event that the bifurcating cut is taken prior to the and offerthe major advantage of providing precision scanning operation, the rightand left halves of the slice are then individually scanned to delineatethe edible loin portions which are then separated.

It will be appreciated that the tuna exhibits a longitudinal dissymmetrysuch that the blood meat portions of a transverse slice are taperedthrough the slice. The cutting tool for separating the edible loinportions of the slice can be angularly disposed in accordance with thistaper to thereby more completely remove the edible loins from theassociated blood meta portions. The angular inclination of the taperthrough the transverse slice, in one embodiment, can be presumed fromthe nature of the particular slice and the position from which it wasseparated from the whole tuna. Altematively, respective oppositesurfaces of the transverse slice can be scanned according to theinvention to determine the exact cross sectional configuration of bothsurfaces of the slice, and to provide corresponding electrical signalsoperative to control cutting apparams, the angular position of which canalso be controlled to follow the tapered boundary of the edible loins.

Although the invention finds especial application to the butchering oftuna or tuna-like fish, it will be appreciated that the invention isalso applicable to other types of fish which can be subdivided intofrozen transverse slices and which exhibit distinguishable light anddark meat portions. The invention can be practised by a variety ofinstrumentalities which are individually known. For example, theparticular scanning apparatus, cutting apparatus and means forpositioning transverse slices for scanning and cutting can take manydifferent forms to suit specific requirements. Accordingly, it is notintended to limit the invention by what has been particularly shown anddescribed, except as indicated in the appended claims.

What is claimed is: l. The method of butchering tuna which is in afrozen condition comprising the steps of:

cutting the loin bearing portion .of said tuna along planesapproximately normal to the major skeletal axis thereof into a pluralityof discrete bilaterally symmetrical frozen slices have predeterminedthicknesses; and scanning a surface of each of said frozen slices toproduce electrical signals representative of the boundary between theedible loin portions thereof and the waste meat portions and operativeto control the movement of cutting apparatus for separating said edibleloin portions. 2. The method of butchering frozen transverse slices oftuna comprising the steps of:

scanning at least one surface of a slice to produce signalsrepresentative of the boundary between the edible loin portions and thewaste meat portions thereof; and

deriving control signals from said electrical signals operative tocontrol the movement of cutting apparatus for separating said edibleloin portions along said boundary.

3. The method according to claim 2 further including the step of:

cutting said slice along said boundary in response to said controlsignals to separate said edible loin portions. i

4. The method according to claim 2 including the further step of:

thawing said at least one surface. of said frozen slice 65 5. The methodaccording to claim 2 wherein said scanning step includes:

scanning both transverse surfaces of said frozen slice to produceelectrical signals representative of the boundary of said edible loinportions at both transverse surfaces and operative to control themovement and angular disposition of cutting apparatus for separatingsaid. edible loin portion along said boundary. 6. The method accordingto claim 2 including the further step of:

cutting said frozen slice along planes generally paral' lel to theneural spine structure thereof, to separate the right and left edibleloin portions of said slice.

7. The method according to claim 2 including the fur ther step of:

removing the viscera disposed within the visceral cavity of saidtransverse slice.

8. The method according to claim 2 including the further step ofskinning said transverse slice.

9. The method according to claim 2 comprising the further steps of:

thawing the skin of said transverse slice to a degree sufficient topermit skinning; and

removing said skin from said transverse slice.

10. The method according to claim 2 wherein said scanning step providessignals representative of the boundary between the edible loin portionsof said frozen transverse slice and the contiguous blood meat portionsthereof.

11. The method according to claim 2 wherein said scanning step providessignals representative of the boundary between the edible loin portionsof said frozen transverse slice and the blood meat portions, visceralcavity and skin of said slice.

12. The method of butchering frozen fish which has previously beensubdivided into a plurality of discrete bilaterally symmetricaltransverse sections having predetermined thicknesses, comprising thesteps of:

positioning each section with respect to scanning apparatus;

scanning said positioned section to produce electrical signalsrepresentative of the surface characteristics thereof; and

deriving control signals representative of the boundary between theedible meat portions and the waste meat portions of the scanned section.

13. A system for butchering frozen tuna which has previously beensubdivided into a plurality of discrete bilaterally symmetricaltransverse sections having predetermined thicknesses, said systemcomprising:

means for scanning a surface of said transverse sections;

means for positioning each of said sections in operative associated withsaid scanning means; means operative in response to said scanning meansfor providing output signals representative of the boundary between theedible loin portions and the waste meat portions of a scanned section;and

cutting means operative in response to said output signals for cuttingsaid edible loin portions along said boundary.

14. The system according to claim 13 wherein said cutting meansincludes:

a cutting head operative to cut through the thickness of said transversesections; and

10 portions of said section and of a second magnitude in the presence ofwaste meat portions of said section. 16. The system according to claim14 wherein said cutting head includes:

a water jet cutter for providing a high pressure defined jet of wateroperative to cut through the thickness of said transverse section.

1. The method of butchering tuna which is in a frozen conditioncomprising the steps of: cutting the loin bearing portion of said tunaalong planes approximately normal to the major skeletal axis thereofinto a plurality of discrete bilaterally symmetrical frozen slices havepredetermined thicknesses; and scanning a surface of each of said frozenslices to produce electrical signals representative of the boundarybetween the edible loin portions thereof and the waste meat portions andoperative to control the movement of cutting apparatus for separatingsaid edible loin portions.
 2. The method of butchering frozen Transverseslices of tuna comprising the steps of: scanning at least one surface ofa slice to produce signals representative of the boundary between theedible loin portions and the waste meat portions thereof; and derivingcontrol signals from said electrical signals operative to control themovement of cutting apparatus for separating said edible loin portionsalong said boundary.
 3. The method according to claim 2 furtherincluding the step of: cutting said slice along said boundary inresponse to said control signals to separate said edible loin portions.4. The method according to claim 2 including the further step of:thawing said at least one surface of said frozen slice to remove a frostlayer which may have formed thereon, and thereafter scanning said atleast one surface to produce said electrical signals.
 5. The methodaccording to claim 2 wherein said scanning step includes: scanning bothtransverse surfaces of said frozen slice to produce electrical signalsrepresentative of the boundary of said edible loin portions at bothtransverse surfaces and operative to control the movement and angulardisposition of cutting apparatus for separating said edible loin portionalong said boundary.
 6. The method according to claim 2 including thefurther step of: cutting said frozen slice along planes generallyparallel to the neural spine structure thereof, to separate the rightand left edible loin portions of said slice.
 7. The method according toclaim 2 including the further step of: removing the viscera disposedwithin the visceral cavity of said transverse slice.
 8. The methodaccording to claim 2 including the further step of skinning saidtransverse slice.
 9. The method according to claim 2 comprising thefurther steps of: thawing the skin of said transverse slice to a degreesufficient to permit skinning; and removing said skin from saidtransverse slice.
 10. The method according to claim 2 wherein saidscanning step provides signals representative of the boundary betweenthe edible loin portions of said frozen transverse slice and thecontiguous blood meat portions thereof.
 11. The method according toclaim 2 wherein said scanning step provides signals representative ofthe boundary between the edible loin portions of said frozen transverseslice and the blood meat portions, visceral cavity and skin of saidslice.
 12. The method of butchering frozen fish which has previouslybeen subdivided into a plurality of discrete bilaterally symmetricaltransverse sections having predetermined thicknesses, comprising thesteps of: positioning each section with respect to scanning apparatus;scanning said positioned section to produce electrical signalsrepresentative of the surface characteristics thereof; and derivingcontrol signals representative of the boundary between the edible meatportions and the waste meat portions of the scanned section.
 13. Asystem for butchering frozen tuna which has previously been subdividedinto a plurality of discrete bilaterally symmetrical transverse sectionshaving predetermined thicknesses, said system comprising: means forscanning a surface of said transverse sections; means for positioningeach of said sections in operative associated with said scanning means;means operative in response to said scanning means for providing outputsignals representative of the boundary between the edible loin portionsand the waste meat portions of a scanned section; and cutting meansoperative in response to said output signals for cutting said edibleloin portions along said boundary.
 14. The system according to claim 13wherein said cutting means includes: a cutting head operative to cutthrough the thickness of said transverse sections; and positioning meanssupporting said cutting head and operative to cause movement thereofalong said boundary in response to said output signals.
 15. The systemaccording To claim 14 wherein said scanning means includes: means forilluminating a surface of said section to be scanned; and sensor meansoperative in response to the reflectivity of said scanned surface toprovide outut signals of a first magnitude in the presence of the edibleloin portions of said section and of a second magnitude in the presenceof waste meat portions of said section.
 16. The system according toclaim 14 wherein said cutting head includes: a water jet cutter forproviding a high pressure defined jet of water operative to cut throughthe thickness of said transverse section.